The driveline (Fig. 1) of the GAZ-53A car consists of two shafts: intermediate 13 and main 10
The intermediate cardan shaft is a thin-walled tube (inner diameter 71 mm, wall thickness 2.1 mm), at the front end of which there is a cardan ending in a flange, and at the rear end there is a splined bushing.
They are bolted to the intermediate shaft on the car in front with the cardan flange to the flange of the driven shaft of the gearbox, in the back - with the bracket of the intermediate support to the cross beam of the frame
The rear end of the intermediate shaft rotates in a ball bearing 12 (GPZ-114), placed in an elastic rubber cushion that receives vibration loads from the driveline.
The main cardan shaft is a thin-walled tube, from the front end of which there is a cardan, ending with a sliding splined fork, from the rear - a cardan, ending with a flange.
The main shaft is fixed as follows: the front end engages with the splined bushing of the intermediate shaft by means of a splined fork, and the rear end is bolted from the cardan flange to the flange of the drive gear shaft of the main gear of the rear axle.
The driveline (Fig. 2) of the GAZ-66 car consists of three shafts: intermediate, front and rear.
The front and rear shafts of the GAZ-66 are exactly the same and differ only in the length between the universal joints when installed on a car due to a sliding spline connection.
The cardan shafts located on the side of the drive axles on the GAZ-66 car have protective stamped caps 11 and 19, which protect the cardan shafts from dirt and water getting into them.
All removable or wear parts that make up the drivelines of GAZ-6b and GAZ-53A cars are interchangeable.
These include crosses, GPZ-804704K needle bearings, flanges, splined and sliding bushings, gland cages, oil seals, etc.
The intermediate support of the cardan shaft of the GAZ-53A car (bearing, rubber cushion, felt seals) is unified with the ZIL-1Z0 car.
Maintenance of cardan gear
Maintenance of the driveline consists of:
- - periodical lubrication of cardan shafts, intermediate support bearing and change of lubricant in the spline connection;
- - checking the fastening of the intermediate support bracket to the frame cross member and fastenings of the cardan flanges to the gearbox and rear axle;
- - checking the tightness of the sliding fork seals;
- - checking backlashes in cardans, splines and intermediate support bearing (only on GAZ-53A);
- - cleaning shafts from dirt.
Lubricate the needle bearings of the cardan shafts through the grease fittings screwed into the crosspieces with gear oil only. It is unacceptable to lubricate them with greases (such as grease).
Lubricate the bearing of the GAZ-53A intermediate support of the cardan shaft with grease through the grease fitting located at the back at the bottom of the support.
Special attention should be paid to the cork seals of the cardan cross and the felt seals of the intermediate support on the GAZ-53A car.
In case of significant shrinkage and loss of elasticity, as well as in case of breakage of cork seals of needle bearings, grease quickly flows out through the seals of the cross, so they should be immediately replaced with new ones.
The bearing of the intermediate support of the cardan shaft on the GAZ-53A car wears out quickly if the loss of sealing qualities of the felt seals of the support is not detected in a timely manner and the worn or destroyed seals are not replaced.
To lubricate the spline joint of the cardan shafts, it is necessary to remove the cardan shaft from the car, disassemble, rinse, lubricate and assemble the spline joint in the following sequence:
- - unscrew the clip of the glands;
- - disconnect spline connection;
- - rinse the slots of the sliding fork and the cavity of the splined sleeve;
- - spread 250 g of grease evenly over the splines of the bushing and the cavity of the sliding fork;
- - insert the slotted sliding fork into the slotted bushing, align the marks on the fork and bushing in the same plane;
- - screw on the seal holder, having previously straightened the position of the seals in the holder. The clip should be screwed by hand to a position where there is not enough hand effort.
It is also necessary to pay special attention to the fastening of the needle bearings of the cardan shafts and to the tightening of the bolts for fastening the connecting flanges of the cardan shafts.
The appearance of gaps in the connection of the flanges leads to the rapid development of holes in the flanges or to the breakage of the bolts.
For greater reliability of the specified connection, the universal joint bolts have a tight fit in the holes of the mating flanges, and the bolts themselves are heat treated to exclude the possibility of their elongation.
Play in the universal joints, spline connection and bearing of the intermediate support (only on the GAZ-53A) can be checked without removing the shaft from the car, by rocking the shaft by hand either around the axis of the shaft or in a vertical plane.
If significant play is found, remove the shaft from the vehicle and repair it.
Gimbal drive failures and how to fix them
- Causes of malfunction
Vibration of cardan shafts and, as a result, vibration of the entire car
- Large dynamic imbalance (imbalance of cardan shafts)
Check for deflection of the shafts and dents on the pipes, whether the forks of the cardan shafts are installed correctly.
Proper installation must be carried out according to the marks (see Fig. 1 and 2), excessive wear of the sliding spline or in the universal joints, and also check the reliability of the fastening of the flanges of the universal joint shafts and the presence of balancing plates.
Replace deformed or bent parts, install the forks according to the marks and dynamically balance the cardan shafts. Permissible unbalance is not more than 50 kgfm in the places where cardan shafts are balanced.
Whistling of the GAZ-53A intermediate cardan shaft support bearing:
- Lack of lubrication in the support bearing
Lubricate the bearing with a grease fitting
- Grease leakage from the bearing
Replace worn felt seals
- Rotating a bearing in a rubber pad
Replace bearing assembly with rubber cushion
Knocking when starting the car from a stop or when accelerating in gears:
- Loosening of cardan shafts on the car
Tighten the driveline mounting bolts
- Increased wear of the splined sliding joint or cardan joint
Replace worn spline or gimbal parts
Lubricant leakage from cardan shafts, spline connection and intermediate support (only on GAZ-53A):
- Wear of oil seals
Replace worn cardan and intermediate bearing seals.
Tighten the sliding fork oil seal cage
To balance the driveline of the GAZ-5ZA car as a whole (i.e., the intermediate and main shafts together) on a special machine.
GAZ-66 cardan shafts should be balanced individually
Bring the angles between the cardan yokes in accordance with fig. 3 and 4
(angle values are given for a fully loaded vehicle in a static state) by replacing worn parts - engine mount rubber pads, intermediate support rubber pad (only on GAZ-53A), transfer case rubber pads
The driveline from the GAZ-66 car is removed by disconnecting the cardan flanges from the flanges of the driven shaft of the gearbox and the drive gear shaft of the final drive.
On a GAZ-53A car, it is necessary to additionally disconnect the intermediate support bracket from the frame cross beam.
Inspection and balancing of parts. Cardan shafts are checked assembled with cardan shafts on a cardan gear removed from the car.
Before disassembling the cardan shaft, measure the total angular play of the cardan shafts, which is obtained due to the wear of the spline connection and the spikes of the cardan crosses.
When checking the backlash (Fig. 5), one of the ends of the cardan shaft is fixed to the other - a torque is applied.
Under the action of a torque of 70 kgcm, play is allowed (without replacement of parts and repairs) up to 0.35 mm, measured at a radius of 35 mm for all shafts of the GAZ-66 car and for the intermediate cardan shaft of the GAZ-53A car.
At the same radius, a backlash of up to 0.17 mm is allowed for the rear propeller shaft of a GAZ-53A car.
On the new cardan shafts of the GAZ-66 car and the intermediate cardan shaft of the GAZ-53A car, backlash is allowed t 0.25 mm, and on the new rear cardan shaft GAZ-53A or one of the cardan shafts of any shaft, play up to 0.12 mm is allowed.
For the new intermediate cardan shaft of the GAZ-53A car and all shafts of the GAZ-66 car, the runout of the shaft at any point along the length of the pipe should be no more than 1 mm.
For the new rear driveshaft of the GAZ-53A car, a runout of no more than 1.2 mm is allowed at any point along the length of the pipe. It is necessary to check the runout (Fig. 6) before balancing the shaft.
Check the amount of radial play in the driveline spline due to wear on the splines. For a new shaft, the amount of play should not exceed 0.08 mm at a radius of 49 mm.
To determine the specified value, fix the intermediate cardan shaft in a vice and turn the sliding fork, setting the indicator leg at a radius of 49 mm.
Replacing the driveline
For the GAZ-53A car, the manufacturer carries out a thorough dynamic balancing of the intermediate and main cardan shafts together (included).
Therefore, you can only change the cardan drive on a GAZ-53A car.
The cardan is replaced in this sequence.
- 1. Clamp the cardan shaft in a vise.
- 2. Unscrew the bolts securing the bearing caps to the cardan yoke and remove the bearing caps.
On the cardan shaft of the GAZ-6b car, where there are protective caps for cardan shafts, you must first unscrew the bolts of the protective cap clamps and slide the cap along the pipe.
- 3. Choose a mandrel whose outer diameter is slightly smaller than the diameter of the cardan bearings.
- 4. Install a mandrel at one of the bearings as shown in fig. 7.
With light hammer blows on the mandrel, remove both needle bearings located on the same axis as the mandrel from the lugs of the cardan yoke. Remove two bearings from the cardan cross.
- 5. Turn the cross and the cardan yoke ¼ turn and push the bearings out of the ears of the second cardan yoke in the same way.
- 6. Remove the cardan cross.
When disassembling the cardan, it should be established whether all the bearings are lubricated and whether there is dirt in the grease, whether the channels of the cross are clogged (a through hole should be visible),
If the individual studs are dry and the bearings and seals are intact, check that all bearings are receiving lubrication. To do this, rinse the cross and wipe the bearings.
Put two bearings on opposite spikes. Clamp the ends of the bearings in a vise so that the crosspiece rotates easily in the fixed bearings. Put on the two remaining bearings and clamp them with a clamp.
Check the ease of rotation of the spikes in the bearings. Lubricate the oiler with a syringe until the valve is fully open. The valve must open fully at a pressure of at least 1 kg/cm2.
If the valve opens at a lower pressure, oil will not flow to all bearings in the new joint.
At a pressure of more than 3.5 kg/cm2, grease can enter through the cork gland, thereby violating its tightness. To check the valve under pressure, you need to screw it into a tee, into which a pressure gauge is screwed and a grease gun is connected.
If the valve cannot be repaired, it should be replaced.
Inspect the spikes of the cross. If there are prints on them - traces of needles, but the total play of the shaft does not exceed the norm, and there are no vibrations and knocks when driving, the cross can be left.
The depth of the dent should not exceed 0.1 mm. If the bearings oscillate on the stud or the stud has worn down to a diameter less than 21.96 mm (nominal 21.986-22.000 mm), then the cross with the bearing assembly should be replaced.
It is allowed to replace individual bearings with the preservation of the cross, when only the bearing, bearing cap, oil seal is damaged or the ring into which the oil seal is pressed is crushed
If individual needles are deformed or at least one of them is lost, the bearing should be replaced.
In case of significant shrinkage and loss of elasticity, cork seals must be replaced. Bearing holes in the forks are allowed to wear up to a diameter of 35.05 mm.
The cardan is assembled in the reverse order of disassembly
After assembly, lubricate the universal joint through the grease fitting in the cross until lubrication appears through the control valve.
Replacing the bearing and seals of the intermediate support of the cardan shaft (only on GAZ-53A)
To replace a bearing and oil seals of the intermediate support of the driveshaft, first remove the driveline from the car.
The bearing and the oil seal of the intermediate support are replaced in the following sequence:
- - unscrew the clip of the glands of the spline connection;
- - disconnect spline connection;
- - remove the support bracket from the rubber cushion;
- - remove the rubber cushion and four brackets of the bearing caps;
- - clamp the intermediate shaft in a vice;
- - bend the locking antennae of the reflective washer from the grooves of the nut;
- - unscrew the nut (Fig. 8) and remove the oil seal deflector;
- - remove the bearing assembly with cages, seals and rear spacer;
- - by lightly tapping the mandrel, first remove the rear race of the stuffing box from the bearing, and then the front one;
- - remove the felt seals from the sockets of the bearing seals.
To determine the technical condition after disassembly, rinse all parts of the cardan shaft support, and then establish by external inspection: the condition of the bearing (its wear), whether the protrusions of the stamped seal cages were in the same plane, and whether the cages were completely pressed onto the outer ring of the bearings.
At the same time, establish whether there is through wear of the gland cages from brackets.
Check if there is a tightness of the felt seals on the surface of the bushings on which they work, or if there is shrinkage of the seal. To do this, without squeezing the stuffing box out of the cage, put it on the removed bushing.
With a serviceable bearing, having detected the above deviations in the relative position of the clips, align the protrusions of the clips by repressing one of them again.
If necessary, re-press the seal cages to failure on the outer ring of the bearing.
If there is a lot of wear on the bearing seals, they are replaced with new ones.
Before installing the felt seals into the cages, be sure to soak the seals in warm oil (for engines) for 15 minutes.
The intermediate support and the cardan shaft of the GAZ-53A car are assembled in the reverse order of disassembly. In this case, you should remember and by all means fulfill the following conditions.
When pressing the seal races onto the bearing, the protrusions of both races must be in line.
When installing the rubber cushion on the bearing, keep in mind that the grease fitting must fall into the slot of the cushion.
By mating the spline connection of the cardan shaft, ensure that the sliding fork lugs are in the same plane with the lugs of the intermediate shaft front propeller shaft welded fork.
A deviation in the position of the indicated forks in one plane is not more than 2º.
When assembling the shafts, this condition is ensured by combining the marks on the splined bushing and the splined fork in one plane. These marks are stamped on the parts during the manufacture of shafts at the factory.
After assembling the intermediate support, it is lubricated through a grease fitting. You can apply lubricant to the support during the assembly of the support.
Replacement of spline seals. To replace the seals of the spline connection of the cardan shaft, perform the following operations.
- 1. Unscrew the clip of the seals.
- 2. Separate the driveshaft flange from the final drive gear shaft flange.
- 3. Disconnect the spline.
- 4. Remove the oil seals from the sliding fork.
By external inspection, check the condition of the seals and the amount of grease in the spline connection, determine the suitability of the seals for further work.
The shaft is assembled in the reverse order of disassembly.
The splined connection is assembled according to the marks on the splined bushing and splined fork.
Screw the stuffing box by hand to a position where there is not enough hand force.